FIGURE 7.

Broadened specificity of TRβ2 for coactivator LXXLL motifs not recognized by TRβ1. The ability of GST-TRβ1 and GST-TRβ2 to bind to the ³⁵S-radiolabeled GRIP1 constructs indicated was assayed as described in the legend to Fig. 4E. A, TR binding of full-length GRIP1 in which LXXLL-1 was mutated to LXXAA. B, TR binding of full-length GRIP1 in which LXXLL-2 was mutated to LXXAA. C, TR binding of full-length GRIP1 in which LXXLL-3 was mutated to LXXAA. D, TR binding of GRIP1 in which LXXLL-2 was mutated to LXXAA and bearing an N-terminal deletion. E, TR binding of GRIP1 in which LXXLL-2 was mutated to LXXAA and bearing a deletion of the Q-rich domain. Statistical confidence symbols are as described in the legend to Fig. 3.